Cable stripping device



Feb. 21, 1967' F. B. STARK 3,304,605

CABLE STRIPPING DEVICE Filed June 29, 1965 INVENTOR.

RANK BENAA Mm TARK BYM, MM 9 1444 United States Patent 3,304,605 CABLESTRIPPING DEVICE Frank Benjamin Stark, Wormleysburg, Pa, assignor to AMPIncorporated, Harrisburg, Pa. Filed June 29, 1965, Ser. No. 467,875 6Claims. (Cl. .30--90.1)

This invention relates to a hand operated rotary cutter and cuttingmethod, and more particularly to a simplified cutting device fordressing or marking the ends of coaxial and shielded wire cables.

Various cutting devices have been evolved for stripping insulatedshielded wire and cable and for cutting non-metallic tubing. Some ofthese prior devices include intricate cable positioning, holding andcutting means with activating arms and levers, and some includemulti-piece housings. These devices are usually cumbersome, diflicult tooperate and expensive to make. The present cutting device is a one piecetubular member with a longitudinal bore partly therethrough and withspaced step-wise slots thereacross. The end of a cable to be dressed isentered into the device via the longitudinal bore, and a cutter blade isutilized in the transverse slots, one slot at a time while the device isrotated about the cable. This strips the cable and prepares it fortermination. The cutter device may be held stationary and the cablerotated within the device if desired.

It is therefore an object of the present invention to provide a new andimproved device for dressing the ends of coaxial cables and insulatedconductors.

Another object is to provide a device of this nature which is compact,portable, easy to use and inexpensive to manufacture.

Another object is the provision of a rotary cutter device which willdress the ends of cables without injuring or fraying the underlayers orthe shielding.

Still another object is the provision of a cutter device which enablesthe measurement and/or marking of the length of the conductor lead andcable braid to be exposed in the stripping process.

Other objects and attainments of the present invention will becomeapparent to those skilled in the art upon a reading of the followingdetailed description when taken in conjunction with the accompanyingdrawings in which there is shown and described an illustrativeembodiment of the invention; it is to be understood, however, that thisembodiment is not intended to be exhaustive nor limiting of theinvention, but is given for the purpose of illustration in order thatothers skilled in the art may fully understand this invention and theprinciples thereof and the manner of applying it in practical use sothat they may modify it in various forms, each as may be best suited tothe conditions of a particular use.

In the drawings:

FIGURE 1 is an exploded perspective view showing a cable being insertedinto a cutter device in accordance with the present invention;

FIGURE 2 is a perspective view showing the cutter device in operation;

FIGURE 3 is a cross-sectional view taken through the cutter device ofFIGURE 1;

FIGURE 3a is a side elevational view of the cutter device of FIGURES 1and 2; and

FIGURES 4 to 6 are views of successive stages in the cable dressingoperation.

Referring now to the drawings and particularly to FIGURE 4, the rotarycutter device C of the present invention embodies a tubular member 2having a central bore 3 with one end thereof partially closed by a Wall4.

Bore 3 is formed of a suitable diameter to accept the smallest to thelargest cable in a given cable range,

3,364,605 Patented Feb. 21, 1967 ICC e.g. RG59, RG62, RG140 and RG210.The above cables are generally the same size in cable O.D., braid O.D.,dielectric OD. and conductor diameter, but vary slightly in constructionand materials. Wall 4 constitutes a positioning means to accommodate acable end bottomed upon insertion of the cable W into the cutter device.A sigh-t hole 6 is provided in wall 4 to allow the operator to inspectthe end of cable W for its proper positioning within cutter C.

First, second and third slots, 8, 9 and 10 respectively, are formed instep-wise array in the bore 3 of member 2. Each slot has substantiallythe same width, but each is of successively greater depth beginning fromfirst slot 8. Slots 8, 9, and 10 are identified by marking numbers;e.g., 1, 2, and 3, which are embossed or engraved on the outer surfaceof the device (FIGURE 3a). This arrangement permits cuts to be made ontocable or wire in a desired sequence. Bore 3 of member 2 is of sufficientdiameter to enable any one of a number of coaxial cables W within agiven ca-ble range to be inserted therein. The depths to which slots 8,9 and 10 are out are respectively equal to the thickness of insulationlayer 12, the combined thickness of insulation layer 12 and braid layer14, and the total thickness of insulation layer 12, braid layer 14 andcable dielectric layer 16 of cable W, FIGURES 4, 5 and 6.

A cutter blade B, e.-g. razor blade or knife blade, is utilized in slots8, 9 and 10 the combination of which constitutes the cutting means bywhich predetermined lengths of cable layers are stripped from cable Wthereby dressing the end of the cable for subsequent termination to acomponent.

In operation, the end of a cable W is inserted into the cutter device C,FIGURE 1, and bottomed against wall 4. The center conductor CD of cableW will be clearly visible at sight hole 6. A cutter blade B is insertedinto slot 10 and biased against cable W by one finger of the operator,FIGURE 2. The cable W may be rotated within cutter device C, or thedevice may be rotated about cable W, whichever is desirable. Thisrotation causes cutter blade B to sever layers 12, 14 and 16, but doesnot allow blade B to touch or otherwise nick center conductor CD, FIGURE4. After a number of rotations, blade B is withdrawn from slot 10 andentered into slot 9. The same above rotation procedure is administeredat this slot. During this rotation, a cut is made equal to the thicknessof layers 12 and 14 which ultimately exposes a short length of cabledielectric, FIGURE 5. The same rotation procedure is then administeredwith blade B in slot 8. This cut is through insulation layer 12 but notthrough braid layer 14. The cable is withdrawn from the device with thevarious layers and combinations being then pulled from the end of thecable. The result is a properly stripped and dressed cable end having asuitable length of exposed center conductor CD, a short section of cabledielectric 16 behind conductor CD and a length of cable braid 14continuous over dielectric 16, FIGURE 6.

It should be noted that the closed end section of the cutter device Cmay be knurled as indicated at K or otherwise serrated, FIGURE 1, tofacilitate the operation of the device. Slots 8, 9 and 10 respectivelymay be numbered 3, 2 and 1, respectively, or otherwise coded to assureproper sequential operation of the device. The device may be numbered orcolor coded to assure its proper use relative to a given cable range.

The cutter device of the present invention may be used as a markingdevice to mark a cable for subsequent cutting. This is desirable onspecial cables having extremely hard jackets and dielectric layers. Inthis case, the cable is marked by using the cutter blades in the slotsof the device whereafter the cable is removed from the device and cut byhand. The cutter device of the present invention is not limited to threeslots, but may have any suitable number of slots to accommodate cablesof various construction.

It should also be noted that a rotary cutter device in accordance withthe present invention may be used to cut pre-deter-mined lengths ofplastic or other non metallic tubing.

It will, therefore, be appreciated that the aforementioned and otherdesirable objectives have been achieved; however, it should beemphasized that the particular embodiment of the invention which isshown and described herein, is intended as merely illustrative and notas restrictive of the invention.

What is claimed is:

1. A rotary cutter device for dressing the ends of coaxial cablecomprising in combination a tubular member and a cutter blade, saidtubular member having a series of transverse axially spaced slots ofdifferent depths related to the radial thickness of the layers of thecable for imposing spaced cuts of different depths in said cable, saidtubular member slots being of a width to receive and limit the insertionof said cutter blade to assure proper cuts in said cable and, saidtubular member further having means at one end defining a stop for cableentered therein which is axially spaced from said slots to accuratelyposition the cable within said tubular member relative to said slots andpre-determined lengths of cable conductor, ca ble dielectric and cablebraid to be exposed or removed.

2. The device of claim 1 wherein said slot depths increase in proportionto the axial spacing thereof from said stop means.

3. A tool for stripping the ends of coaxial electrical cable comprisingin combination a tubular member and a cutter blade, gauge means in saidtubular member for imposing spaced cuts of varying depths in said cable,said tubular member including an axial bore adapted to receive andsupport a cable inserted therein, said gauge means being comprised of anumber of spaced transverse slots through a side wall of said tubularmember,

which are of a Width to receive and limit the insertion of said cutterblade therein for imposing said spaced cuts of varying depth in saidcable, said bore being closed on one end thereof by an end wall defininga stop means for cable inserted therein with said wall including anaperture for visual inspection to assure proper cable position withinsaid tubular member.

4. The tool of claim 3 wherein said slots are angularly disposed withadjacent slots in different segments of walls of said tubular member.

5. The tool according to claim 3 wherein said aperture is comprised of asmall longitudinal opening in said end wall concentric with the centerconductor of said cable whereby said center conductor is visible to theoperator of said cutter device when said cable is in proper position insaid cutter device, during the stripping operation.

6. A tool for stripping insulated coaxial and shielded cable comprisinga cylindrical member having a central bore partly therethrough toreceive a cable end, wall means on one end of said bore, inspectionmeans in said wall means including a hole for inspecting said cable endinside said bore, and slot means on said cylindrical member to receive acutting blade for performing a series of spaced cuts of different depthsin said cable to remove layers thereof of a desired axial length wherebyto strip cable, said slot means being marked to permit all of said cutsto be accomplished in a desired sequence or to permit any one of saidcuts to be made separately.

References Cited by the Examiner UNITED STATES PATENTS 1,725,114 8/1929Van Gelderen 81-9.5 2,120,398 6/1938 Edwards et a1. 3090.6' 2,984,9055/1961 Harmon 8l-9.5 3,161,088 12/1964 Tolman 819.5

WILLIAM FELDMAN, Primary Examiner.

MILTON S. MEHR, Examiner,

1. A ROTARY CUTTER DEVICE FOR DRESSING THE ENDS OF COAXIAL CABLECOMPRISING IN COMBINATION A TUBULAR MEMBER AND A CUTTER BLADE, SAIDTUBULAR MEMBER HAVING A SERIES OF TRANSVERSE AXIALLY SPACED SLOTS OFDIFFERENT DEPTHS RELATED TO THE RADIAL THICKNESS OF THE LAYERS OF THECABLE FOR IMPOSING SPACED CUTS OF DIFFERENT DEPTHS IN SAID CABLE, SAIDTUBULAR MEMBER SLOTS BEING OF A WIDTH TO RECEIVE AND LIMIT THE INSERTIONOF SAID CUTTER BLADE TO ASSURE PROPER CUTS IN SAID CABLE AND, SAIDTUBULAR MEMBER FURTHER HAVING MEANS AT ONE END DEFINING A STOP FOR CABLEENTERED THEREIN WHICH IS AXIALLY SPACED FROM SAID SLOTS TO ACCURATELYPOSITION THE CABLE WITHIN SAID TUBULAR MEMBER RELATIVE TO SAID SLOTS ANDPRE-DETERMINED LENGTHS OF CABLE CONDUCTOR, CABLE DIELECTRIC AND CABLEBRAID TO BE EXPOSED OR REMOVED.